SEOmator - SEO website analysis & audit tool
Google News - Comprehensive up-to-date news coverage, aggregated from sources all over the world by Google News.
SerpSquirrel - Check & track Google SERP
Digg - Digg delivers the most interesting and talked-about stories on the Web right now.
SEO Dub - AI-powered SEO audit and planning tool
SEO Book - Learn SEO: An on-page SEO tutorial